On the band gaps and effective masses of mono and dual doped monolayer graphene

Dublin Core

Título

On the band gaps and effective masses of mono and dual doped monolayer graphene

Tema

NANOTECNOLOGIA

NANOMATERIALES DE CARBONO

GRAFENO

CALCULOS FUNCIONALES DE DENSIDAD

BIBLIOGRAFIA NACIONAL QUIMICA

2017

Abstract

Herein, we studied the variation of band gaps and effective masses of doped graphene. The gaps of mono and dual doped graphene decay with respect to unit cell size following a curve of the form βNα. The exponent has a small variation and an average value of −3/2. The pre-exponential term presents a larger dispersion as the heteroatom is changed. In some cases, such as Si-doped graphene, the gaps could not be fitted to the aforementioned type of curve because the gaps are close to zero. Using these curves for P-doped graphene, we estimated that for a unit cell with 5000 atoms, one P atom is expected to open a gap close to 0.05 eV, as indicated by HSE calculations. The effective masses of holes and electrons also follow a curve of the form βNα, as the unit cell is increased. Yet, in contrast with the results obtained for gaps, the exponents determined for Si, P and S doped graphene exhibit a larger variation. For dual-doped graphene, the introduction of a second dopant to P-doped graphene (namely, B or N), decreases the effective masses. This result suggests that dual-doped graphene is an interesting material to develop graphene based electronic devices.